At the opposite end of the "performance tuning linux" spectrum is the "Raspberry Pi" platform. Using under 5W, costing as low as $35, running "Raspian" linux on 700MHz and 500MB and an SD card, it isn't for rocket scientists. So I thought it was worth dusting off an old freepascal console codes program and trying to adapt it to TCL. TCL is a nice command and scripting language, and might better provide a console user interface, thus saving graphics work. Amazing how old treasures are quickly dumped these days. Those of us old enough to remember mechanical typewriters, tube TVs, and solenoid switches might appreciate Linux on this end of the performance spectrum. Linda Kateley wrote: > Not sure if you had any responses to this, but this sounds kind of old > to me. When hyperthreading first came out, it would flush the l1 cache > when you moved the new thread context onto the cpu. I don't think it > does this anymore. I used to do that kind of recommendation in low > latency so you wouldn't keep squashy the l1. If you had a single > threaded app, it wouldn't make sense to keep clearing. Another solution > to that is to give the app it's own cpu. Nowadays, you can barely buy a > server without a bunch of cores/sockets. > > The second one.. is more current. For sometime, chips slowed themselves > down..to conserve power, if they don't have work to do, but the speed up > hasn't been an issue for sometime. > > I have done perf tuning for years(on solaris, not linux) but the best > thing is almost always more/better resources. Also ssd is probably the > best thing to come around for performance in years. Low end disks do > like 100-300 iops. SSD's can be anywhere from 1-20k iops. Disk is > regularly the bottleneck. > > My favorite perf tuning for low latency network app is bind network > interrupts to a cpu or set of cpu's. Not cpu 0 or 1. Interrupts will > usually cause whatever is running to park, then have to reload. The > others are usually double caching of same data. > > The multipath tcp thing sounds really similar to some of the > technologies around infiniband. Trying to think of application? > > On 7/31/14, 6:59 AM, canito at dalan.us wrote: >> Good Morning- >> >> Last night I watched a couple of Performance Tuning videos on Youtube >> and hearing a couple of suggestions I've never heard before, prompted >> me to write and ask what are some of the tunables you find most useful? >> >> Two suggestions for performance that I have not heard up to now: >> >> 1.) Disabling hyper-threading for latency sensitive applications. >> 2.) Disabling power management in the BIOS. >> >> Also just learn of MultipathTCP (MPTCP) which I haven't found any of >> the "enterprise" distros having support for it. One of the speakers >> discussed performance degradation using bonding. Has anyone else >> experienced this? What are the better alternatives for bonding >> interfaces? >> >> Hope you-all have a good day! >> >> SDA >> >> _______________________________________________ >> TCLUG Mailing List - Minneapolis/St. Paul, Minnesota >> tclug-list at mn-linux.org >> http://mailman.mn-linux.org/mailman/listinfo/tclug-list > > _______________________________________________ > TCLUG Mailing List - Minneapolis/St. Paul, Minnesota > tclug-list at mn-linux.org > http://mailman.mn-linux.org/mailman/listinfo/tclug-list >